The invention relates to a messaging service in a wireless telecommunications system enabling the transmission of various message types, such as text, images, speech, video images or other data or combinations thereof from a sender to a recipient using the same transmission mechanism, and more particularly to a messaging service in a mobile communications system.
Mobile communications systems have been developed since a need has arisen for people to freely move away from fixed terminals without making it more difficult to reach them. Services offered through mobile stations have improved with the mobile communications systems. Various new forms of services are currently being created for what are known as the third generation mobile communications systems, such as the Universal Mobile Telecommunications System (UMTS) and IMT-2000 (International Mobile Telecommunications 2000), and for current mobile communications systems, such as the Pan-European mobile communications system GSM (Global System for Mobile communications), including the General Packet Radio Service (GPRS) currently being standardized in the GSM phase 2+ in ETSI (European Telecommunications Standard Institute).
The GPRS service is used for providing packet data transmission between mobile data terminals and external data networks, since the GSM network functions as an access network. One of the conditions set for the GPRS service is that it must operate together with various external data networks, such as the Internet or X.25 networks. The GPRS service and the GSM network should therefore be able to serve all users, irrespective of the type of data networks they wish to be connected to through the GSM network. This means that the GSM network and GPRS service must support and process different network addressing methods and data packet formats. The data packet processing also comprises routing of packets in a packet radio network. In addition, the users should be able to roam from their home GPRS network to a visited GPRS network, whose operator backbone network may support a different protocol (for example CLNP) than the home network (for example X.25).
Known messaging services include short message services and voice mail services. Text messages can be sent as short messages. Voice mail services are in general answering services transmitting voice messages. However, a drawback is that neither of said services enable the transmission of images or video images, not to mention the transmission of messages including multimedia. Another problem is that a text message is sent to a different service centre than a voice message. Still another problem is that the size, or the duration, of at least a voice message is limited.